iCloud Keychain feature questions

Sorry if this is in the wrong thread but I wasn't able to find an iCloud one.

Has anyone ever used this feature? If so, how well does it work?

Also, is data stored on your device or on Apple's iCloud servers? At the keynote, I know that they talked about any payment information related to Apple pay being saved on your phone so Apple can't access it, but I'm wondering if it's the same with keychain.

Firstly, the concept of keychain - just like your browser or any other password managers keychains are used to store usernames and password. It was stored locally but with iCloud, just like everything else it is saved on the iCloud. If you are in the iOS ecosystem it will be available across all your devices instantly. The best part is password recommendations. I love this feature and have used it on a lot of websites. I don't have to remember the passwords and it will autofill for me across the devices.

Yes, I have used it on Mavericks and Yosemite and it works like charm on iOS 8 and iOS 7. If I need to find a particular login in the keychain there is an option to do that within the keychain settings within Safari on iOS settings so I can use it on windows PCs if required.

I haven't heard any negative feedback on the iCloud keychain on multiple threads. The best option is to check it out yourself.